Any writing. Grammar, punctuation, and spelling were always easy, but I never knew what to write.
Also, I often skipped homework and believe that I was right to do so. Even though I've been out of school since 2008 and have no children, I still maintain that the school has zero right to assign anything to be done outside of school.
That sounds like par for the course in the US but the kind of thing that the EU would have a law against.